Planar sided air shaping inserts for filter bags

Abstract

Air shaping mouth inserts for bag type air filters formed as planar sided tubes of rectangular and triangular cross section are inserted into the open ends of the bags. Their mouths are sealed to the bag rim so that air flow is restricted to the interior of the tube insert. This type of insert facilitates shaping and distribution of the reverse jet cleaning pulse by rotating the tubes around the axis or by altering the straight sides to unbalance the cross section of the air flow path.

What is claimed as new and for which Letters Patent of the United States is desired, is: 
     
       1. An air shaping insert for filter bag mouths of a multiple bag filter assembly in which the filter bags extend from a tube sheet which separates a dirty air region from a filtered air region and in which the bag mouths open into the filtered air region, the insert comprising: a sealing means which holds the filter bag onto the tube sheet so that the filter bag seals around a hole in the tube sheet and restricts air flow through the tube sheet to air which passes through the bag mouth;   an insert disc concentric with the sealing means and slideably attached to it so that the insert disc may be rotated relative to the sealing means, the insert disc including an opening;   an insert body attached at the opening of the insert disc, determining the configuration of the opening and extending into the filter bag, the insert body being formed of planar sides extending transverse to the tube sheet, and the insert body having straight-sided cross sections.   
     
     
       2. The air shaping insert of claim 1 wherein the cross sections of the insert body are triangles. 
     
     
       3. The air shaping insert of claim 1 wherein the cross sections of the insert body are rectangular. 
     
     
       4. The air shaping insert of claim 1 further including bendable junctions between the planar sides of the insert body to permit adjustment of the angles of the joints to adjust the cross section of the insert body. 
     
     
       5. The air shaping insert of claim 1 further including filler volumes attached to the planar sides of the insert body to adjust the cross section of the insert body. 
     
     
       6. The air shaping insert of claim 1 further including a "L" shaped bend in one side of the insert body, with the small leg of the "L" oriented approximately in the plane of the mouth of the bag, to reduce the cross section of the insert body.